Plugins for extending Groups

We’re starting to see some really cool initiatives on our BP based alumni site, which is awesome. One member created a Group called “Film Forum” which is starting to take off with multiple threads , wire posts, etc.

Wanting to enrich the experience for them, I was wondering if anyone knew of WP plugins of any sort that might be useful in adding features like a “ratings” system (say for films in this example) and other ways to make the group a little more data “aware” a la keeping track of films members discuss, etc. I’m not tring to turn this into IMDB or Rotten Tomatoes, but if I can add to the experience I’d like to. Thanks for any insights.